Lubricant pad for bearings



NOV. 16, 1954 R. ETzKoRN LUBRICANT PAD FOR BEARINGS Filed Oct. 18 1949JNI/ENTOR.

g"WLF ETz KoR/v BY United States Patent LUBRICANT PAD Fon BEARINGSRudolf Etzkom, Murg, Baden, Germany, assignor, by mesne assignments, toCefas Aktiengesellschaft, Zurich, Switzerland, a corporation ofSwitzerland Application October 18, 1949, Serial No. 122,137

Claims priority, application Switzerland October 22, 1948 7 Claims. (Cl.308-243) My present invention relates to improvements in capillaryaction textile lubricant pads for bearings, in particular for railwaycar journals; and the main object of my improvements is to continuouslyand uniformly also incorporate into the contact surface such lubricantswhich cannot be supplied through capillary action, without, however,impairing the capillary-action oil supply.

The bearings of railway car journals often comprise an upper brassagainst which the journals are pressed through the weight of the vehicleand a lubricant pad which contacts the journal from below. The said padcomprises a textile strand structure and a wire support therefor, and isspring-pressed against the journal. On the side adjacent the journal,the threads are woven loop-like into the pad, while at the bottom sidethe threads are immersed in form of wicks in the oil chamber. The saidwicks suck oil up into the fabric loops or thread nooses which, byvirtue of the spring pressure, contact and oil the axle journal. Arequirement for such action is, however, that the axle-journal surfacesare of high and uniform smoothness, Without hair cracks and the like.

In power-vehicle motors and gears, the use of graphited oils has provedof Value. Graphite, as is well known in the art, is capable of smoothingout minor rough spots in bearing surfaces and increasing the lubricatingcapacity of the oil. Through the use of oils containing graphite incolloidal dispersion, the operating properties of the bearings and,thus, the safety of operation are substantially improved. The use ofsuch oils, however, is impossible in those cases in which wicks areused, since the latter although capable of adsorbing the oil, are notcapable of feeding the colloidal graphite to the point of lubrication.It has not been possible, therefore, up to now to exploit the advantagesafforded through the use of graphite oil.

It has been attempted to coat the threads of lubricant pads withgraphite, as is done, e. g., in the case of stufiingbox packings, butthe results were disappointing, since the graphite tends to plug thecapillaries. It thus has not been possible, up to the present, tosatisfactorily feed graphite to axle-journals of the type indicated.

According to my present invention, the threads contacting theaxle-journal surface consist, partly at least, of artificial fibres inwhich lubricant particles are stored or embodied. In one example, allthe threads contacting the journal consist of single fibres in which areembodied minute particles of a lubricant, preferably distributeduniformly over the entire fibre cross-section. In another example, thesaid fibres are present in the loop in cornpany with other natural orartificial fibres. In any case, it is of essence that lubricantparticles are embodied in at least part of the threads in the sectionsin which they contact the axle-journal. With a view of simplifying themanufacture of the pad, the wicks which are immersed in the oil, may bemade of the same fibres as the thread loops.

By embodying in the fibrous mass solid lubricants or, again, liquidlubricants which cannot be fed through capillary action to the axlejournals, these lubricants still can be supplied to the contact face. Itthus is possible to utilize the favorable action of solid materials suchas graphite, talcum, or of highly viscous oils and fats.

Artificial fibres made from solutions having a basis of cellulose, suchas may be made e. g. according to the viscose process or thecuprammonium silk process, are best suited for the purpose of my presentinvention, the

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finely` dispersed lubricant being incorporated in the spinning solutionand anchored byvirtue of the spinning process in the fibres uniformlydistributed across the entire fibre cross-section.

In order to understand clearly this invention an example is illustratedin the accompanying drawing, in which Fig. 1 shows a sectional view of alubricant structed according to this invention, and

Fig. 2 illustrates a cross section through a number of particularfibers.

Fig. l shows a tissuev or cloth 1 into which threads 2 are woven orsewed. The threads form loops on the upper part of the tissue 1. Belowthecloth 1 are provided threads 3 which act as wicks.

The pad is fastened to a frame (not shown). In the interest of betterclarity only a few of the threads 3 are shown in the drawing.

According to this invention the fibers of the threads 2 are madeartificially and particles of lubricants are incorporated into ytheparticular fibers.

Fig. 2 illustrates a cross-section 'through a number of particularfibers 4 of the threads 2. It is'shown, how the particles 5 of lubricantare incorporated into the fibers.

It is not necessary that lubricant particles be incorporated also intothe fibers of the threads 3, although in order to have a simplerfabrication of the pad, threads 2 and 3 may consist of the samematerial.

The threads 3 hanging from the tissue 1 reach into an oil container andoil is supplied by capillary action to the threads 2, which are incontact with the part to be lubricated, for instance a journal of anaxle. If by friction between the threads 2 and the moving part to belubricated the fibers of the thread gradually wear out, the lubricantincorporated therein is set free and takes part in the lubricationprocess.

The quantity of incorporated lubricant may vary in wide limits. Theupper limit is defined by the requisite rubbing strength and stabilityof the fibre, which depends on one hand on the nature of the bearingstress and, on the other hand, on the combined use of fibres having noincorporations. In general, lubricant contents from l0 to 80 percent byweight of the entire fiber mass have proved useful, figured for theimpregnated fiber and not considering eventual other fibers used incombination therewith.

According to one example of my present invention, there may be provided,aside from the artificial fibres impregnated with graphite, talcum orthe like, also artificial fibres impregnated with another lubricant,finely dispersed therein, such as fats or oils. The latter preferablyshall have a higher boiling point and flash point than, for instance,the oils which are fed by capillary action through the wicks to thecontact surfaces.

A preferred example of such latter combination comprises, in addition tothe solid lubricant, fat or oil embodied in the same fiber.

In use, as already stated above the pads according to my presentinvention continuously provide lubricant for the contact surfaces, inaddition to the oil fed through the wicks by capillary action, owing toa slight rubbing wear of the fibers. The result of such additionallubrication is a substantial improvement of the lubricating property ofthe sucked-up oil. It has to be further noted that the fibers used forthe pad according to my present invention, in contradistinction withpads of prior art, shall have a stability as high as possible, i. e. thefibres shall oppose as much as possible a smoothing and felting on thecontact surface due to friction under the pressure of the contactspring. It has been found that the fiber which contains solidssubstantially maintains its initial shaped despite the pressing andfriction, and thus is more suitable for feeding oil to the contact facesthan the fibers used up to the present time. The stability of the fibersaccording to my present invention can be -attributed to the largequantity of embodied solids on one hand, and may be further enhanced byan appropriate process of manufacture.

The oil output of the wick, i. e. the feed of oil to the axle journal,is not impaired by the incorporations in the ber. On the contrary, incomparison with the pad connatural fibres used in prior art, such outputcan be substantiall-yincreasedby using fibers ofsmall single standard orfineness, whereby the number of capillaries is increased.

When, owing tolack^' ofi oil', soiling and.l the like-, ther temperatureof the` bearing` is. raised:` above its. normalf temperature ofoperation, the. fiber4 mass. is; destroyed, and relatively largequantities of the embodied: lubricantsA are set free. The operatingproperties thereby. are improved. insuch degree, also. at these higherbearing tem-A peratures, as to prevent in most cases further overheatingand seizing of the bearings. Testsy of lubricating pads according tomypresentY invention, have shown that they areV substantially more.reliable in. operation than pads of prior art.

What'I claim as new and. desire to secure by Letters Patent', is:

1.- A lubricant textilematerial for bearings, comprising, incombination, elongated threads. each thread being formed of a plurality;of fibers andV having first portions adapted toy Contactv the surfaceto. belubricated and second portions adapted to be immersed in a bathofliquid lubricant so. that liquid lubricant may be carried to said first:portions by capillary action; at least some of. said fibers consistingof a composition ofsynthetic substance. andparticles of a lubricatingsubstance embedded therein, so. thatI upon disintegration. of: thesynthetic substance forming part of said fiber the lubricating substanceembedded therein is freed for lubricating action.

2. A lubricant textile materiali for bearings, compris. 30

ing, in combination, a. plurality ofelongated yarns each composed ofindividual fibers; at least some of said fibers consisting of acomposition of: a synthetic substance and particles of a. lubricatinglsubstance embedded therein, so that upon disintegration of the syntheticsubstance forming part of said fiber the lubricating substance embeddedtherein is freed for lubricating action,` said yarns having the fibersthereof arranged formingy interstices between themselves andi havingafirst portionadapted to contact the surface to be lubricated andasecond portion adapted to be immersed in a bath of liqudlubricant,sothat liquidlubricant may'be carried to said first portions of' saidyarnsV by` capillary action .in the interstced space between the fibers.

3. A lubricant textile material forbearings, compris- 4. ing, incombination, elongated threads each thread being formed' of` apluralityof fibersV and having first portions adapted to contact thesurface to be lubricated and second portions adapted to be immersed in abath of liquid lubricant so that liquid lubricant may be carried to saidfirst portions by capillary action; at least some of said fibersconsisting of a. composition of synthetic substance and partclesofalubricating substance embedded therein, so.` that upon disintegration ofthe synthetic substance forming part Qff said fiber ther lubricatingsubstance embedded thereink is freed for lubricating action, saidparticles of lubricating substance having a higher boiling oit.andflashl point than said liquid. lubricant in said 4. A lubricantvtextile material as defined in claim 1, wherein said lubricatingsubstance is graphite.

5. A lubricant textile material1 as defined in claim l, wherein saidlubricating substance is talcum.

6,. A lubricant textile material as defined' in claim l, wherein saidlubricating substance is a highly viscous oil.

7. A lubricant textile material' as defined in claim 1, wherein saidsynthetic substance is a synthetic cellulose base substance.

References Cited in the. file. Qi this Patent UNI-TED STATES, PATENTSNumber. Name Date 3,215,966 Piercer Sept. 8, 1885 733,156.5 Cole` July7, 1903 765,176 Gill July 19, 1904 787,752A Griin Apr. 18, 1905 997,501Howe July 11, 1911 1542733401 Woodman Aug. 29, 1922 2,126,042. ReinzAug. 9, 1938 2116.6J739 Karplus: July 18, 1939 2,291,483 Miller July 28,1942 233,137,986; Fryl Dec. 28, 1943 FOREIGN PATENTS Number CountrykDate 1,234: GreatBritain A. D. 1867

